Chair frame



FIG. 1 is a front perspective view of a chair frame showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a back view thereof;

FIG. 4 is a side view, the opposite side being a mirror image thereof; and,

FIG. 5 is a top view thereof.

The broken lines shown in the drawing are for illustrative purposes only and form no part of the claimed design. 

CLAIM The ornamental design for chair frame, as shown and described. 